1. Field of the Invention
The present invention relates to a door closing device and in particular to a door closing device for bringing a door which is in an imperfectly closed condition into a perfectly closed condition.
2. Description of the Prior Art
U.S. Pat. No. 4,986,579 granted to Ishikawa on Jan. 22, 1991, discloses a door closing device which, in order to bring a door from an imperfectly closed condition into a perfectly closed condition, includes a door-closing mechanism associated with a door-lock mechanism. The door-closing mechanism has an active-lever which is adapted to be rotated, and a passive-lever which is operatively connected to the door lock mechanism. The rotation of the active-lever is transmitted to the passive-lever via a pin disposed therebetween, thereby resulting in rotation of the passive-lever. In that way, the door-lock mechanism is actuated to cause the door to be brought into the perfectly closed condition. In the foregoing structure, when the rotating passive-lever is brought into engagement with a latch member, the rotation of the passive-lever is adapted to actuate the door-lock device in order to establish the perfectly or fully closed condition of the door.
In the foregoing structure, the plane of rotation of the passive-lever and the plane of rotation of the latch member make an angle of about 90 degrees with each other. This means that when the passive-lever and the latch member are engaged while under rotational movement, a sliding friction will be generated along two directions. Thus, a loss is generated in the transmission of torque from the passive-lever to the latch member.